The invention relates to an apparatus for loading items to be washed with an air flow, comprising a substantially closed first channel system, for forcibly guiding an air flow loading the items to be washed, in which first channel system are arranged a treatment chamber for receiving the items to be washed, a blower for driving the air flow, a heater for heating the air flow before the items to be washed are loaded, and a cooler for cooling the air flow after the items to be washed have been loaded. The invention also relates to a method for loading items to be washed with an air flow, which is forcibly guided in a first channel system described above.
Such an apparatus and such a method are revealed from EP 0 467 188 B1, the disclosure thereof being included in the present disclosure in its entirety. In the apparatus there for drying items to be washed, the heater and the cooler are components of a heat pump device and, in this heat pump device, the cooler forms an evaporator and the heater forms a condenser for an operating fluid circulating in a corresponding circuit. The first channel system, in which the air flow is guided, is substantially closed—this means that during operation according to the intended purpose the air flow circulates substantially without leakages, but does not adopt a substantially higher pressure than the air surrounding the apparatus. The air flow is in this case substantially driven by the blower and thus forcibly guided through the first channel system; convection and similar lifting effects play a subordinate role, however, for driving the air flow. If required, the channel system may be connected to the surroundings by opening a flap, in particular in order to discharge from the apparatus a part of the air flow heated during operation and to replace said part of the air flow with relatively cool air from the surroundings. The treatment chamber for receiving the items to be washed is designed as a rotatable drum.
A washing machine is revealed from DE 1 410 206 A, in which items to be washed are not only able to be washed but also dried. The publication shows a plurality of alternatives for the additional devices required therefor; in particular, an electrical heating apparatus may be provided for heating an air flow used for drying items to be washed and a simple heat exchanger for cooling the heated air flow after loading the items to be washed, but the heater and the cooler may also form part of a heat pump device. The heat pump device may be designed as the heat pump device disclosed in EP 0 467 188 B1, but it may also be a heat pump device which operates with Peltier elements for utilizing the thermoelectrical effect.
An apparatus for drying items to be washed of the type described in the introduction is revealed from DE 19 738 735 C2, in which a heat pump device is used which operates according to an absorption principle.
An apparatus for drying items to be washed revealed from an English extract from the data collection “Patent Abstracts of Japan” belonging to JP 08 057 194 A, which in turn corresponds to the type described in the introduction, contains in its first channel system in addition to a heater and a cooler which both form part of a heat pump device which may be thermoelectrically operated, an additional heat exchanger arranged upstream of the cooler for cooling the air flow discharged by the items to be washed and an additional heating device arranged downstream of the heater for further heating of the air flow before the loading of the items to be washed. An apparatus for drying items to be washed is also revealed from DE 3 509 549 A1, which in addition to a heat pump device with a cooler and heater comprises a further heating device as well as additional heat transport devices such as gravitation heat pipes.
It is common to all disclosed devices and methods of the prior art that the components thereof required for loading the items to be washed with the air flow are arranged in succession in the channel system provided for guiding the air flow. Such an arrangement sets specific requirements for implementation in an apparatus intended for and suitable for use in a normal domestic environment. Due to the limited amount of available space, these requirements may dictate that components of the channel system have to be designed relatively small and therefore with a relatively high flow resistance for the air flow; this may considerably impair the effect of the drying process taking place in the apparatus, as in this case an air flow with a restricted volumetric flow rate has to be forced through a channel system, possibly causing detrimental frictional losses and throttle losses. This problem is particularly pronounced when a heat pump device is to be inserted in the apparatus, in particular a thermoelectric heat pump device. Particularly in the case of the thermoelectric heat pump device, in an apparatus which is used in a domestic washer-dryer with conventional external dimensions, the channel system has to be repeatedly folded.
A drying apparatus for drying items to be washed by means of an air flow is revealed from DE 32 04 718 A1 which comprises a drying chamber for receiving the items to be washed, a heating element for heating up the air flow and a condensation element for extracting moisture from the air flow. In this connection, lifting effects and negative lifting effects, which occur as a result of heating or cooling the air flow or a portion of the air flow, are utilized for forcing the air flow in each case. In particular, a lifting effect in the heating element is utilized in each disclosed embodiment of the drying apparatus. The condensation element may contain a combination of a blower and a valve for assisting its effect; the heating element and the condensation element may be corresponding components of a heat pump system.
One of ordinary skill in the art at the time of the invention will understand the basis, function and application of Peltier elements.